Irving S. Brecher (January 17, 1914 – November 17, 2008) was a screenwriter who wrote for the Marx Brothers among many others; he was the only writer to get sole credit on a Marx Brothers film, penning the screenplays for At the Circus (1939) and Go West (1940). He was also one of the numerous uncredited writers on the screenplay of The Wizard of Oz (1939). Some of his other screenplays were Shadow of the Thin Man (1941), Ziegfeld Follies (1946) and Bye Bye Birdie (1963).